GE Aerospace recently demonstrated what it believes is the first hypersonic dual-mode ramjet (DMRJ) rig test with rotating detonation combustion (RDC) (earlier post) in a supersonic flow stream. This could help enable high-speed, long-range flight with increased efficiency.

A dual mode ramjet (DMR) is a ramjet engine which can be operated in both subsonic and supersonic combustion mode. RDC enables higher thrust generation more efficiently, at an overall smaller engine size and weight, by combusting the fuel through supersonically tavelling detonation waves instead of a standard combustion system that powers traditional jet engines today. This in turn delivers high performance in a small volume.

The milestone and overall portfolio of programs position GE Aerospace to pursue multiple opportunities in the hypersonic sector as it prepares to launch as a standalone company in Q2 of 2024.

The successful high-speed propulsion DMRJ demonstration is part of a comprehensive portfolio of technology programs GE Aerospace is developing and scaling to advance hypersonic capabilities, including high-temperature materials and high-temperature electronics.

These technologies are the product of more than a decade’s worth of direct hypersonic-related efforts advanced by GE Aerospace Research and several decades of developments for its GE Aerospace engine business in key areas such as high-temperature ceramic matrix composites (CMCs), silicon carbide power electronics, additive technologies, and advanced thermal management.

The acquisition of Innoveering last year gave GE Aerospace dual mode ramjet engine capabilities that were rapidly augmented with GE Aerospace Research’s decade’s long work in RDC and several decades of GE Aerospace experience in high Mach research and engine development programs.

Mark Rettig, Vice President & General Manager, Edison Works Business & Technology Development, GE Aerospace,said that the team has moved very fast, noting it took just 12 months from start to finish for the DMRJ with RDC demonstration. The team is on track with its goal to demonstrate a full DMRJ with RDC at scale next year.

The development of high-speed ramjet propulsion capabilities is a key anchor point of other key advancements in hypersonic technologies, including:

• High-Temperature Materials: GE Aerospace is the only aerospace OEM using ceramic matrix composites in the high pressure turbines on commercial aircraft. These decades of materials innovation in superalloys have delivered higher temperature capabilities and durability that have enabled commercial engines to operate more efficiently over time.

• High-Temperature Electronics: GE Aerospace researchers recently demonstrated the first believed Silicon Carbide (SiC) MOSFETs that can operate at temperatures exceeding 800 ˚C, along with other recent advancements in SiC technology that have created scalable 600 ˚C-capable electronics to control and monitor hypersonic vehicles in extreme high temperature operating environments. GE Aerospace has amassed a leading IP portfolio in SiC over two decades and already offers SiC- based electrical power products with power levels from kilowatts to megawatts for harsh environments in aerospace, industrial, and military applications.